Introduction: The article presents the current state of issues regarding the diagnosis of pathological conditions for forensic medical experts, in particular the study of normal muscle tissue and in the presence of hemorrhages. Particular attention is paid to biophysical research methods with evidence-based accuracy, objectivity, reproducibility, and rapid results. Objectives: The purpose of the research was to study the possibilities of using spectrophotopolyarimetric methods to analyze and determine the relationship of morphological structure of biological tissues with the temporal dynamics of changes in their optical parameters, to establish the possibility of differentiating necrotic changes and signs of damage by applying Mueller matrices of human muscle tissue samples. Results: During the study, we found a number of features and patterns of change in the properties of the laser beam as a result of passing through biological tissue. Polarization-correlation methods provide new, objective information about the dynamics of change in laser polarimetric imaging of morphological structure of biological tissues. By analyzing the statistical distributions of the ellipticity of polarization of laser images of normal human muscle tissue and in the presence of hemorrhages, the possibility of identifying the relationship between the development of statistically significant changes with increasing time of death and the possibility of differentiating them are considered. Conclusion: Based on these results, we can conclude that employing laser polarization methods will allow us to open new doors in the study of the biological tissues of the human body. The results showed the effectiveness of the studied methodology and the prospect of further research in this direction.

Introduction: Fatal intoxications with alcohol and carbon monoxide are the most common causes of poisoning that occur in forensic medical practice. Therefore, the differential diagnosis of these intoxications is extremely important. To solve this problem, we propose the use of the method of azimuthal-invariant polarization Mueller-matrix microscopy of histological sections of biological tissues (BT). Objectives: The purpose of the study was to establish statistically significant criteria for differentiation of the cause of death in case of alcohol poisoning (AP) and carbon monoxide poisoning (CMP) by using azimuthal-invariant polarization Mueller-matrix microscopy of polycrystalline fractions of histological sections of organs and blood films of the human body. Results: A number of characteristic features have been identified that have not been previously described and allow to objectively differentiate the cause of death in the case of AP and CMP, namely Ek – 0.95±0.045 and 1.81±0.092 in the study of histological sections of the myocardium;  Ek – 0,19±0,011 and 1,11±0,094 – polycrystalline blood films. Analysis of the obtained data revealed a good level of accuracy in the study of histological sections of the myocardium (As 85%) and polycrystalline blood films (As 88%). Conclusion: Thus, developed and tested method of azimuthal-invariant polarization Mueller-matrix microscopy allows to differentiate the cause of death in cases of AP and CMP.